SPOILER ALERT: This blog is for people watching the first series of Masters of Sex at UK broadcast pace. Don't read on if you haven't seen episode three – and if you've seen later episodes, please do not leave spoilers.

'If you want to lead an unconventional life, you've got to learn to hide in plain sight'

When Provost Scully gives that advice to a young, more gauche Bill Masters in 1945, it seems initially to be merely a way of telling his awkward protege how to get on in life. By the end of the episode, however, that conversation resonates in an entirely different way, thanks to the revelation that Scully – the loving family man tossing hot dogs in front of his adoring daughter in flashbacks – also pays for sex with handsome young hustlers. Hiding in plain sight indeed.

The painful conversation between the two old friends that followed was the highlight of a well-paced episode in which we also met Betty's goofy pretzel king, were given further evidence that Libby is not a pushover and learned more about the orgasm habits of prostitutes than Masters, as least, appeared comfortable being told. In the end, though, it was the revelation that Masters owed his entire career to Scully, and yet was still prepared to blackmail his former mentor in the name of his study, that lingered. This is not simply scientific curiosity. It's an obsession, and lord help those who stand in his way.

That said, one of the things that most fascinates me about Masters' character is the way he completely divides the professional and personal. As such, he was very kind to Betty, post-operatively giving her his best bedside manner – and, indeed, standing down the doctors who mocked her profession during surgery – but in private he was arrogant, dismissive and even cruel, both about her hopes and the fact he had to operate at all. It was a striking reversal of the way that split would usually have been portrayed.

'Just another hard-working girl doing the best she can'

A mixed week for Virginia saw her continuing to push for recognition for her work on the study. She's right – Masters can't have it both ways; if she's good enough to help in the study at night, she can't simply go back to being his secretary by day. She also finds further inspiration with the arrival of female obstetrician, Lillian DePaul.

She proved her warmth in the brothel scenes: Masters might hate the fact that his study features "outliers and misfits", but he wouldn't have progressed this far without Virginia changing the questions and responding in a recognisably human way when the girls tell their tales. That said, I'm in two minds about the line she crossed in telling Libby the truth: it was absolutely the most human response, and it was wrong that Libby was being told everything was her fault; however, it breached patient confidentiality in a major way. I wouldn't like to be in her shoes if (or when) Masters finds out.

Notes and observations

• Speaking of Libby, she continues to break my heart. A lesser drama would have made her a weaker character, but what's fascinating is that she's prepared to stand her corner. The problem is, she's fighting from a weaker position than her opponent and husband. Her little hope-chest of children's clothes was quietly devastating.

• Poor old Ethan, too. Yes, he's a horse's ass, but I could see his motivation. It's frustrating feeling that you're capable of doing something but never getting your chance to shine. It's also clear that Masters' mentoring, unlike that of Scully, was somewhat lacking in encouragement, even before the fallout from the Virginia affair. Would the quads really have died had he been left solely in charge? The show left it vague, but it's clear that in shooting for glory, involving the newspapers and cutting out Masters he dug his career grave.

• There were some interesting parallels between Virginia and Ethan, too. Both are desperate to advance, both are ambitious and neither have much of a problem with cutting corners to achieve their ends. Had they been slightly different people, they might have made a formidable pair.

• Masters (or writer Michelle Ashford) has a thing about Everest and sexual conflict. Two weeks ago, it was Hillary and Tenzing; this week, it was poor, doomed George Mallory and "because it's there".

• The homosexuality subplot was an interesting one, given Masters and Johnsons' later hugely controversial works. The show has chosen to present Masters as being driven entirely by concern for his data, but it was more complex than that. Those who don't mind being spoiled should go here.

• One of the things the show most strikingly demonstrates is how willingly people will commit to something if they think it's for the sake of science. The young hustler admitted he was intrigued because he liked the idea of people studying him, suggesting it would lead to a form of validation.

• Dr DePaul was played by Julianne Nicholson, who – as Boardwalk Empire fans will know – does a great line in calm, collected and very icy indeed.

• Finally, I was glad the pretzel king existed, although I can't help thinking this isn't going to end well for anyone involved.

Quote of the week

"Humans have taken the basic impulse for sex and turned it into some unrecognisable ordeal" – Masters' rant against romance and etiquette speaks to the cynic within us all.

Sexual advice of the week

"You're a man of science, I'll just grab Carl and show you how it's done" – Masters gets rather more than he bargained for after asking for some male specimens for his study.

So, what do you think? Should Virginia have left Libby in the dark? Can Betty have her happy-ever-after? Can Masters and Scully rebuild their friendship, and does Ethan even have a career? As always, let us know in the comments below.

Sarah Hughes: Season one bows out with an exceptionally strong double-bill that forced our characters to confront the truth. Cue some more soul-searching, and heartbreaking scenes between Barton and Margaret